CDC Weight-for-Stature Growth Chart (77-121.5 cm)
Plot a child's weight relative to standing height using CDC reference data. This chart assesses body proportionality across the CDC stature range of 77 to 121.5 cm, which is why stature matters more than chronological age here.
LMS Method: Z = ((X/M)^L - 1) / (L x S)
How It Works
This calculator uses the CDC weight-for-stature reference to compare a child's weight with other children of the same standing height. Unlike weight-for-age, it does not need date of birth because stature itself is the lookup axis. The chart is only valid across the CDC standing-height range of 77 to 121.5 cm, which means it is most useful for shorter children who are old enough to stand but not yet tall enough to age out of the table. The LMS method computes a stature-specific Z-score and converts that to a percentile so you can judge body proportionality rather than age-based size.
Example Problem
A girl with a standing height of 110 cm weighs 19.3 kg. What is her weight-for-stature percentile?
- Select Girl because CDC weight-for-stature uses sex-specific reference data.
- Enter 110 cm for standing height and 19.3 kg for weight.
- The calculator looks up the CDC LMS parameters for girls at a stature of 110 cm.
- Those LMS values convert the entered weight into a Z-score relative to the CDC median at that stature.
- The Z-score is converted into a percentile that tells you how weight compares with peers of the same standing height.
- A result near the 50th percentile means the child's weight is close to the CDC median for that stature.
Because this chart is stature-indexed, it is especially helpful when you want a quick body-proportionality check without doing a separate age-based comparison first.
Key Concepts
Weight-for-stature is similar to weight-for-length, but it uses standing height instead of recumbent length. It answers a different question than weight-for-age: not 'is this child large or small for age?' but 'is this child heavy or light for this height?' In the CDC system it is mainly useful while a child still falls inside the 77 to 121.5 cm standing-height range. For most children older than 2 years, BMI-for-age is the preferred screening tool for overweight and obesity, so weight-for-stature is best treated as a complementary view rather than a replacement.
Applications
- Assessing body proportionality in children aged 2 and older
- Screening when a child's exact age is uncertain
- Complementary assessment alongside BMI-for-age
- Monitoring nutritional status in community health settings
- Evaluating children with growth disorders affecting height and weight differently
- Explaining to parents why stature-based and age-based charts can tell slightly different stories
Common Mistakes
- Using recumbent length instead of standing height — this chart requires standing stature
- Confusing weight-for-stature with weight-for-length (which uses recumbent length for children under 2)
- Using weight-for-stature as the sole obesity screening tool — BMI-for-age is recommended for children over 2
- Entering height in inches without selecting the correct unit
- Not accounting for the child's growth phase — a child in early puberty may have different proportions than a pre-pubertal child
- Treating the label 'CDC 2-20' as permission to use this chart beyond 121.5 cm when the actual lookup table stops there
Frequently Asked Questions
Why does this calculator not ask for age?
CDC weight-for-stature is a stature-only chart — it asks whether weight is proportional to standing height, regardless of age. The chart covers a narrow stature window (77–121.5 cm) where children have transitioned to standing measurement but are too young for adult-style BMI interpretation. Once a child grows past 121.5 cm tall, BMI-for-age replaces this chart as the recommended weight-status screen.
What stature range does this calculator cover?
This calculator covers standing heights from 77 cm to 121.5 cm. Below that range, use weight-for-length if the child is still measured recumbent. Above that range, switch to BMI-for-age rather than stretching this chart past its supported lookup table.
How is weight-for-stature different from weight-for-length?
Weight-for-length uses recumbent length (lying down) for children under 2. Weight-for-stature uses standing height for children 2 and older. Standing height is about 0.7 cm shorter than recumbent length.
When should I use weight-for-stature vs. BMI?
BMI-for-age is the recommended screening tool for overweight and obesity in children over 2. Weight-for-stature is a useful complement, especially when BMI cannot be calculated or when age is uncertain.
Is this chart really useful for all children age 2 to 20?
No. The CDC 2-20 label refers to the broader age group that uses standing height, but the actual weight-for-stature lookup table only runs from 77 to 121.5 cm. Many older children are too tall for it and should be assessed with BMI-for-age instead.
What do the percentile ranges mean?
Below the 5th percentile may indicate underweight. The 5th to 85th percentile is considered healthy weight. The 85th to 95th percentile suggests overweight. Above the 95th percentile suggests obesity.
Can I use inches and pounds?
Yes. The calculator accepts either cm or inches for stature and either kg or pounds for weight, then converts the values internally before applying the CDC LMS lookup.
Reference: CDC Growth Charts: United States. National Center for Health Statistics, 2000. https://www.cdc.gov/growthcharts/
Worked Examples
Kindergarten screening
A girl 110 cm tall weighing 19.3 kg — where does she fall?
A pediatrician is checking whether a 110 cm girl is proportionate for her height. Because weight-for-stature ignores age, the CDC lookup uses the stature-specific LMS row directly.
- Knowns: sex girl, stature 110.0 cm, weight 19.3 kg
- CDC stature-specific LMS lookup at 110.0 cm (girls)
- The LMS method computes a Z-score from the entered weight relative to the median at that stature
- The resulting percentile tells you whether her weight is proportionate to her standing height
about the 50th percentile — very close to the CDC median for girls of that stature.
This chart is most useful while the child remains inside the CDC stature plotting range of 77 to 121.5 cm.
US-units visit
A boy 40 in tall weighing 39 lb — what percentile?
A parent reports a standing height of 40 in and a weight of 39 lb. The calculator converts both to canonical units internally before applying the CDC stature-specific LMS method.
- Knowns: sex boy, stature 40.0 in -> 101.6 cm, weight 39.0 lb -> 17.69 kg
- CDC weight-for-stature uses stature as the independent variable, not age
- The percentile compares the converted weight with the CDC reference distribution at 101.6 cm
- Using the Load button resets both unit dropdowns first so the authored in/lb values are interpreted correctly
a healthy-range percentile for a boy in the low-100-cm stature range.
If a prior session was in kg/cm, the worked-example loader flips the unit selectors before the values land, so there is no stale carry-over.
BMI cross-check
A 121 cm child weighing 31 kg sits near the top of the stature chart — what next?
A child near the upper edge of the CDC stature table measures 121 cm and 31 kg. Weight-for-stature can still be read here, but this is exactly the kind of case where BMI-for-age should be checked alongside it.
- Knowns: stature 121.0 cm, weight 31.0 kg
- The CDC weight-for-stature table still applies because 121.0 cm is inside the supported range
- A very high percentile here signals body proportionality above the CDC reference median
- For overweight/obesity screening above age 2, BMI-for-age remains the preferred companion chart
a very high percentile — use it as a prompt to review BMI-for-age too.
Once stature exceeds 121.5 cm, move to BMI-for-age rather than trying to stretch this chart beyond its supported scope.
Related Calculators
- Weight-for-Age (CDC, 2-20 yr)
- Stature-for-Age (CDC, 2-20 yr)
- Extended BMI-for-Age (CDC, 2-20 yr)
- Z-Score Calculator — Convert z-scores to percentiles and probabilities
- Weight Loss Calculator — Calculate calorie deficit for weight goals
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